Twinrix Rapid Schedule Third Dose Timing When Day 21 is Missed

Recommended Timing for the Delayed Third Dose

The Centers for Disease Control and Prevention recommends that if the 21-day mark for the third dose of Twinrix on the rapid schedule is missed, administer it as soon as possible within the 21-30 day window, and if that window is also missed, give it immediately when the patient returns—the series does not need to be restarted 1, 2
The Advisory Committee on Immunization Practices guidelines state that the Twinrix accelerated schedule allows for the third dose to be given between 21-30 days after the first dose, not strictly on day 21, allowing for flexibility in administration 1, 2

The Advisory Committee on Immunization Practices provides clear guidance that applies to all hepatitis B-containing vaccines, including Twinrix, stating that the series should never be restarted when the schedule is interrupted 1, 2
If only the third dose has been delayed, it should be administered as soon as possible, according to the Advisory Committee on Immunization Practices 1, 2

The Centers for Disease Control and Prevention recommends that the fourth dose at 12 months remains essential for long-term protection, and should be given 12 months after the first dose, not adjusted based on when the third dose was administered 1, 2